Another Colorado squawfish swam up the Redlands Fish Ladder on
the Gunnison River near Grand Junction, Colo., Wednesday (July
23) morning, the third endangered fish to use the 350-foot-long
channel in the past two weeks and the fourth since the structure
was completed last year.

The recent use of the ladder by squawfish probably is because
river flows now are receding and water temperatures are rising,
said Bob Burdick of the U.S. Fish and Wildlife Service in Grand
Junction, Colo. Biologists say this is an encouraging sign about
the ladder's potential success.

"It's noteworthy that we have seen three squawfish go
through the ladder in the last 14 days," Burdick said.
"Their movement may be related to spawning."

The fish found Wednesday was a 23-inch, 3 1/2-pound Colorado
squawfish that had migrated to the ladder from more than 100
miles downstream, a discovery made possible because of a
previously implanted electronic tag routinely used in endangered
fish research. By waving an electronic bar code-like scanner
under the belly of the fish, U.S. Fish and Wildlife Service
researchers identified it as No. 1F41386206, which Utah fishery
biologists had captured in 1995 in the Colorado River near Moab.

In addition to the four endangered fish, to date nearly 15,000
other native fish, such as flannelmouth suckers, bluehead suckers
and roundtail chubs, have passed through the structure, reaching
portions of the Gunnison River that had been off-limits for
nearly a century. The man-made ladder has re-created a more
naturally functioning river environment, despite the presence of
the 12-foot-high concrete dam.

"The lower Colorado River Basin (downstream of Lake
Powell) has been fragmented by dams and diversions that prevent
fish from making their normal migrations, and many native fish
have started to decline in number", Burdick said. "We
want to prevent that from happening in the upper Basin before the
numbers of fish get too low."

Before the ladder was built, when Gunnison River water reached
the Redlands Diversion Dam, it all spilled over the top. Now, a
flow of 25 cubic feet per second is diverted through the fish
ladder. After entering at the bottom, fish swim up a series of
steps to a "holding area" at the top. Biologists then
sort and count the fish before releasing endangered and other
native fish upstream.